Discovery of Mummified Leg of Unknown Creature in Altai, Siberia

A mountaineer discovered a leg of an unknown creature in Altai, Siberia, at 3000 meters altitude. Scientists from the Veterinary Academy and Altai Agrarian University examined it, noting its resemblance to a human leg but with unique features like a big toe with three phalanxes. The leg, covered in red hair, suggests bipedal movement on snow. X-rays revealed it to be several thousand years old, with no known animal match. The limb was well-preserved due to natural mummification.

What did Sergei Semulov notice about the leg that prompted him to bring it back?

What does the presence of red hair on the leg suggest about the creature's habitat?